What is dry cask nuclear waste storage?

Q. My question has to do with Yucca Mountain, which is proposed to be the nation's first nuclear waste dump site. Building the site is now supposed to cost taxpayers $32 billion more than was originally estimated, so a lot of Utah residents I know are understandably upset about the increased price tag, and insisting that storing nuclear waste on site in "dry cask" storage would be safer and more effective. What exactly is dry cask storage, and would it really better than storing nuclear waste at Yucca Mountain? – Sandy, UT

A. Right now, there are two methods of storing nuclear waste. One involves storing spent (toxic) fuel at the bottom of large concrete steel-lined pools while it cools—a process that takes anywhere from one to five years. The other method is dry cask storage, which involves storing cooled fuel in large, heavy steel cylinders that sit above ground and provide leak-tight containment.

The Nuclear Regulatory Commission says that both methods are safe and effective for temporary nuclear waste storage, according to Scott Burnell, NRC spokesperson. But the key word here is “temporary.” Though the dry casks can last for decades, the more than 130 nuclear waste storage sites spread across 39 states were never meant to provide permanent storage. That’s where Yucca Mountain comes in. Nuclear waste storage in Yucca would essentially use the same type of casks mentioned above—except larger and designed to last for thousands of years. Another key difference is that the casks would literally be stored under the mountain—about a thousand feet deep. Plus, nobody lives on Yucca Mountain, points out the Department of Energy, which makes storing the waste there a lot safer than sprinkling it across the countryside.

Of course, there are drawbacks to using Yucca Mountain for storage. Many advocacy groups are worried that it’s not safe to transport nuclear waste across 43 states, that the casks aren’t durable, and that because Yucca Mountain falls along several fault lines it could prove an unstable storage place. “The idea of geologic disposal is that the waste is supposed to stay put,” says Steve Frishman of the Nevada Agency for Nuclear Projects. Frishman advocates above-ground dry cask storage instead, saying that it would provide a reasonable level of safety until the U.S. can figure out how to properly dispose of the waste. Burnell agrees, saying that “dry cask storage is considered safe and acceptable today, and the question of whether Yucca Moutain is safe and acceptable hasn’t been answered.”

But since dry cask storage is temporary, the government will have to act eventually. The only silver lining in this nuclear mess is that constant bickering over Yucca may have prompted the government to consider whether a different path altogether should be considered—one that could involve recycling nuclear waste, says Burnell. For now, the government seems intent on practicing its infamous “wait and see” method.

Story by Jessica A. Knoblauch. This article originally appeared in "Plenty" in July 2008.